JPH08281544A - Machining method of workpiece for optics - Google Patents

Abstract

PURPOSE: To facilitate the machining of a concex or a concave circular arc having constantly fixed curvature to an optical workpiece, for instance a sectional shape being parallel to an optical axis and perpendicular to main scanning direction, as desired accuracy is simply obtained. CONSTITUTION: A rotary body 2a to which a cutting tool 1 is fixed is rotated round a rotary shaft 2 set up as an axis, and on the other hand, an optical workpiece 3 is compositely moved in a direction (x) opposite to a rotary axis A and a direction (y) along the center A to execute cutting on one plane 3a along the rotary axis A of the workpiece 3, and a circular arc having a fixed curvature is formed in a cut part on a perpendicular section to the rotary axis A of the optical workpiece 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing an optical work piece.

[0002]

2. Description of the Related Art Aspherical surface processing is sometimes required for an optical lens or an optical processed product such as a mold for manufacturing the optical lens. In some cases, the optical work piece needs to be processed into a convex or concave circular arc (mirror surface processing) having a constant curvature in the cross-sectional shape parallel to the optical axis and orthogonal to the main scanning direction.

[0003]

However, in the conventional rotary cutting by a machine tool, that is, in the cutting in which a cutting tool, for example, is advanced while rotating an optical workpiece, the aspherical surface machining as described above is performed. Is impossible.

Although it is conceivable to carry out the above-mentioned processing by using a tool such as a grinder, there is a problem that desired accuracy cannot be obtained, that is, mirror surface processing cannot be performed.

Therefore, according to the present invention, a desired accuracy can be easily obtained, and a convex or concave portion having a constant curvature is always formed on the optical work piece in a sectional shape parallel to the optical axis and orthogonal to the main scanning direction. It is an object of the present invention to provide a method for processing an optical work piece capable of processing an arc.

[0006]

In order to achieve the above object, a method for processing an optical work piece according to a first aspect of the present invention is such that a rotating body having a cutting tool fixed thereto is rotated about an axis of rotation, The optical work piece is synthetically moved in a direction facing the rotation axis and along the direction, and one surface along the rotation axis of the optical work piece is cut, and the rotation of the optical work piece is performed. An arc having a constant curvature was formed in the cut portion in a cross section perpendicular to the axis.

In order to achieve the above-mentioned object, the method for processing an optical work piece according to a second aspect uses an optical scanning lens or a mold thereof as the optical work piece in addition to the above-mentioned first aspect.
It is characterized in that the surface corresponding to the convex lens surface or the concave lens surface is cut.

[0008]

According to the processing method of the optical work piece in such means, the rotating body to which the cutting tool is fixed is rotated about the rotation axis, while the optical work piece is moved to the rotation axis center. Are combinedly moved in a direction opposite to and along the direction, and cutting is performed on one surface along the rotation axis of the optical work piece, and in a cutting portion in a cross section perpendicular to the rotation axis center of the optical work piece. , An arc with a constant curvature is always formed. This aspherical surface processing is simple and desired accuracy is obtained.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view illustrating an example of an optical workpiece and a processing apparatus to which the processing method of the present invention is applied. In the figure, reference numeral 1 denotes, for example, a cutting tool as a cutting tool, and the cutting tool 1 is detachably attached to a tool holder 2a as a rotating body. The cutting tool holder 2a is fixed to the tip of a main shaft 2 as a rotary shaft of a machine tool (not shown), and the mounting direction of the cutting tool 1 is a direction orthogonal to the rotary shaft center A. That is, when the spindle 2 rotates, the cutting tool 1
It is adapted to rotate around the axis A of the main shaft 2. As the cutting tool 1, for example, a diamond tool is used.

A metal mold 3, for example, is disposed as an optical workpiece on the side (right side in the drawing) of the cutting tool 1, and the metal mold 3 is detachably fixed to a moving body (not shown). This moving body is moved in the direction x facing the rotation axis A by the first moving means (not shown), and the first moving means is moved by the second moving means (not shown) in the rotation axis A. It is designed to be moved in the direction y along. That is,
The mold 3 and the moving body are moved along the rotation axis A while moving in the direction x facing the rotation axis A.

The surface of the mold 3 that needs to be cut (the surface that needs to be mirror-finished; the left side surface in the figure) corresponds to the optical lens surface formed by the mold 3 and has a rotating shaft. Heart A
It becomes uneven along.

Therefore, the cutting tool 1 is rotated by the main shaft 2 and the mold 3 is moved by a predetermined amount in the opposite direction x while moving in the direction y along the axis of rotation A by the moving means (in the lateral direction in the drawing). When moved), a concave cutting surface 3a is formed on one surface (uneven surface) of the mold 3 along the rotation axis A, and a cutting portion of the mold 3 in a vertical cross section with respect to the rotation axis A. In addition, as shown in FIG. 2, a concave arc 3b having a constant curvature is always formed. This cutting surface 3a
The processing accuracy of (1) is not due to the grinder or the like described in the prior art but is due to a cutting tool such as a diamond bite, so processing with desired accuracy (mirror surface processing) is achieved.

As described above, in this embodiment, the desired accuracy can be easily obtained, and the concave arc 3b having a constant curvature in the vertical sectional shape with respect to the rotation axis A with respect to the mold 3 can be obtained.
Can be processed.

FIGS. 3A to 3D show, for example, an optical lens as an optical workpiece which is aspherical processed by the above processing device. The optical lens 13 is used in, for example, an optical scanning device, and is, for example, a surface tilt correction system lens having an anamorphic surface.

Therefore, instead of the mold 3, the lens 1 is used.
When 3 is used for the above processing device and the same processing as above is performed,
One surface of the lens 13 along the axis A of rotation (convex surface; FIG.
As shown in FIGS. 3C and 3D, a concave cutting surface 13a is formed on the right side surface in FIG. 3A, and a cutting portion of the lens 13 in a cross section perpendicular to the rotation axis A is formed as shown in FIGS. , A concave arc 13b having a constant curvature r2 is always formed.

That is, the same concave aspherical surface processing as described above can be performed on the lens 13 while easily obtaining the desired accuracy.

FIG. 4 is a side explanatory view showing another example of an optical workpiece and a processing apparatus to which the processing method of the present invention is applied, which is the same as the previous embodiment and has the same function. Are given the same reference numerals.

In this embodiment, the spindle 2 of the machine tool is
The tool holder 12a fixed to the lower end has a cup shape with the lower end opened.
A cutting bite 1 is detachably attached to the open side end (lower end in the drawing) of 2a, the attachment direction of which is orthogonal to the rotation axis A and the tip of which is directed to the axis A. The size of the hollow portion inside the bite holder 12a is such that a mold 23, which will be described later, can be inserted.

A metal mold 23, for example, is placed as an optical work piece in the hollow portion on the side of the tip of the cutting tool 1 and inside the tool holder 12a. This metal mold 23 is the same as that of the previous embodiment. The moving means moves along the rotation axis A while moving in the direction x facing the rotation axis A.

The surface of the die 23 that needs to be cut (the surface that needs to be mirror-finished; the left side surface in the figure) corresponds to the optical lens surface formed by the die 23, It is uneven along the heart A.

Therefore, the cutting tool 1 is rotated by the main shaft 2, and the die 23 is moved by a predetermined amount in the opposite direction x while being moved in the direction y along the rotational axis A by the moving means (in the lateral direction in the drawing). (Moving), the cutting surface 2 having a convex shape on one surface (uneven surface) of the mold 23 along the rotation axis A.
3a is formed, and as shown in FIG. 5, a convex arc 23b having a constant curvature is always formed in a cut portion of the die 23 in a cross section perpendicular to the rotation axis A.

That is, in this embodiment, the convex arc 2 having a constant curvature in the vertical cross-section shape with respect to the rotation axis A is always obtained with respect to the die 23 while easily obtaining a desired accuracy.
It is possible to process 3b. It is of course possible to use a lens instead of the mold 23.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say, for example, in the above-described embodiment, the lens is used for the optical scanning device, but the same processing may be performed on the lens used for another optical device or the mold thereof. You can Further, the object to be processed is not limited to the lens or its mold.

[0024]

As described above, according to the processing method of the optical workpiece of the present invention, the rotating body to which the cutting tool is fixed is
While rotating around the axis of rotation, the optical work piece,
By synthetically moving in the direction opposite to the rotation axis and along the direction, cutting is performed on one surface along the rotation axis of the optical work piece, and in a vertical section with respect to the rotation axis center of the optical work piece. Since a circular arc having a constant curvature is formed in the cutting portion, a desired accuracy can be easily obtained, and a convex or convex portion that always has a constant curvature in the vertical sectional shape with respect to the rotation axis with respect to the optical work piece. It is possible to process a concave arc.

[Brief description of drawings]

FIG. 1 is a side view illustrating an example of an optical workpiece and a processing apparatus to which a processing method of the present invention is applied.

FIG. 2 is a vertical sectional view of the optical work piece used in FIG.

3A and 3B show an optical scanning lens used as an optical workpiece, wherein FIG. 3A is a side view, FIG. 3B is a front view, FIG. 3C is a sectional view taken along line AA, and FIG. It is a BB sectional view.

FIG. 4 is an explanatory side view showing another example of an optical workpiece and a processing apparatus to which the processing method of the present invention is applied.

5 is a vertical cross-sectional view of the optical workpiece used in FIG. 4 with respect to the rotation axis.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cutting tool 2 Rotating shafts 2a, 12a Rotating body 3,23 Molds (workpiece for optics) 3a, 13a, 23a Cutting surfaces 3b, 13b, 23b along a rotation axis of a workpiece for optics 13 Arcs with constant curvature 13 Optical scanning lens (workpiece for optics) x direction facing the rotation axis y direction along the rotation axis

Claims (2)

[Claims] 1. A rotating body, to which a cutting tool is fixed, is rotated about an axis of rotation, while an optical work piece is synthetically moved in a direction facing the axis of rotation and a direction along the optical axis. A method for processing an optical workpiece in which an arc having a constant curvature is formed in a cut portion in a cross section perpendicular to the rotational axis of the optical workpiece by cutting one surface along the rotational axis of the workpiece for optical processing. . 2. The method for processing an optical workpiece according to claim 1, wherein an optical scanning lens or a mold thereof is used as the optical workpiece, and a surface corresponding to the convex lens surface or the concave lens surface is cut. And a method of processing an optical workpiece.